Hydroxyethylthio hydroxyethylamino-phenyl-azo and -azoxy dyestuffs

ABSTRACT

A process for the preparation of the sulphone of the formula &lt;IMAGE&gt; (1)  consists in reductive cleavage of azo/azoxy dyestuffs of the formula   &lt;IMAGE&gt; (6)  where D is a radical of a diazo component from the benzene or naphthalene series. The invention also relates to the azo/azoxy dyestuffs mentioned.

This is a continuation-in-part application of Ser. No. 07/760,798 filedSep. 16, 1991, now abandoned, which was a division of application Ser.No. 07/603,097 filed Oct. 25, 1990, now U.S. Pat. No. 5,107,025.

The invention relates to a process for the preparation of[5-amino-2-(2-hydroxyethylamino)phenyl] (2-hydroxyethyl) sulphone of theformula ##STR3## characterized in that benzothiazoles of the formula##STR4## in which

E is H or CH₃, are reacted with ethylene oxide in an aqueous reactionmedium to give N-formyl- or N-acetyl-N-(2-hydroxyethyl)anilinederivatives of the formula ##STR5## which are then hydrolyzed to givethe aniline derivative of the formula ##STR6## which is then coupledonto a diazotized amine D--NH₂ to give monoazo dyestuffs of the formula##STR7## the azo dyestuffs (5) are then oxidized to the azo/azoxydyestuffs of the formula ##STR8## which are then cleaved reductively ina manner known per se to give D--NH₂ and (1).

The invention also relates to the new azo and azo/azoxy dyestuffs of theformulae (5) and (6).

D represents the radical of a diazo component, in particular from thebenzene or naphthalene series.

D can be substituted by customary substituents, for example Cl, Br, F,C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy, carbalkoxy, carboxyl, amino, alkylamino,dialkylamino, sulphonamido, alkylsulphonyl and in particular sulpho.Preferably, those substituents which do not undergo any change duringthe oxidation and reduction are suitable. The alkyl groups can containcustomary substituents.

Those azo and azo/azoxy dyestuffs of the formulae (5) and (6) arepreferred in which the radical D is selected in such a manner that afterthe reduction of (6) to D--NH₂ and (1) the diazo component D--NH₂ can beeasily separated off and again be used in the synthetic sequence.Examples of these types of radicals D are ##STR9## it being possible forthe benzene and naphthalene rings to contain further substituents, forexample Cl, Br, C₁ -C₄ -alkyl, C₁ -C₄ -alkoxy or carboxyl.

Sulpho-containing or carboxyl-containing diazo components have theadvantage that the oxidation and the reduction can be carried out in anaqueous reaction medium.

Azo and azo/azoxy dyestuffs of the formulae ##STR10## are preferred,since the reduction of (8) uniformly only yields (1). (7) can beprepared by diazotization of (1) and coupling onto (4).

The reaction of the benzothiazoles (2) with excess ethylene oxide ispreferably carried out in water at temperatures between 20° and 120° C.,preferably between 40° and 90° C., and in an autoclave under a pressureof 0.2 to 2.0 bar. The ethylene oxide is metered in at such a rate thata pH of 8 to 12, preferably 9.0 to 10.5, is reached. During thisreaction, the benzothiazole probably passes through the intermediatestages ##STR11## Thus, by simple addition of ethylene oxide, aqueoussolutions of 2-(2-hydroxyethylmercapto)-N-acyl-N-(2-hydroxyethyl)anilineof the formula (3) are surprisingly obtained directly from thebenzothiazoles (2).

The ethoxylation reaction can also be carried out in a reaction mediumcomposed of water and a water-miscible organic solvent. Additions ofemulsifiers or phase-transfer catalysts can accelerate the reaction. Inprinciple, the reaction solutions can be directly further reacted.

The N-formyl- and N-acetylaniline derivative of the formula (3) can behydrolysed not only under acidic but also under alkaline reactionconditions at temperatures of 80° to 120° C., if appropriate underpressure. The free aniline base of the formula (4) separates at pHvalues above 7, i.e. under alkaline conditions, in the form of an oilphase.

The coupling of (4) onto diazotized amines D--NH₂ to give dyestuffs ofthe formula (5) is most advantageously carried out at 0° to 30° C. in apH range of 1.0 to 5.0 in an aqueous medium. Here, too, the use ofemulsifiers or coupling accelerators, such as, for example, urea, canprove advantageous. The dyestuffs (5) are in most cases obtained in theform of crystalline compounds or can be salted out as such. Since thecoupling reactions proceed in most cases relatively uniformly, theintermediate (5) can often be oxidized directly without isolation togive azo/azoxy dyestuffs of the formula (6). In this step, the use ofhydrogen peroxide in the presence of catalytic amounts of tungstates hasproved advantageous. The oxidation is carried out in aqueous medium at20° to 100° C., preferably at 40° to 80° C. and pH values of 6 to 8. Theoxidation passes through the corresponding sulphoxide compounds of theformula ##STR12## as intermediates, which can be monitored bychromatography. Further suitable oxidizing agents are, for example, alsoperborates, persulphates, or persulphonic acids.

The azo/azoxy dyestuffs of the formula (6) can be isolated as yellow tored, crystalline, water-soluble compounds. Upon protonation, theirsolutions show a distinct bathochromic shift. In most dyestuffs (6), theazo content predominates; as a rule, the azoxy content is limited to 5%,such as, for example, in (8). The azo dyestuff (8a) can be obtainedrelatively uniformly by recrystallization from water or alcohol.##STR13##

The reduction of (6) or (8) or (8a) to (1) and D--NH₂ can be carried outby methods such as described by R. Schroter in Handbuch fur praparativeMethoden der organischen Chemie (Handbook of preparative methods inorganic chemistry), Houben-Weyl, Volume XI, Part 1, pages 522 to 531.According to this handbook, reduction using sodium dithionite or glucoseor, alternatively, catalytic reduction using hydrogen is suitable.Suitable catalysts are primarily Raney nickel, palladium/carbon orplatinum compounds. The reductions are preferably carried out in water,water/alcohol mixtures or alcohols at 20° to 80° C.

In the case of (8) and (8a), a uniform solution of (1) is obtained. (1)can be directly further reacted in this form, for example it can becondensed with chloranil or, alternatively, diazotized or isolated as acrystalline substance by concentrating the solution.

In all other cases, the reduction leads to a solution or suspension of(1) and D--NH₂. The latter should therefore be already selected as adiazo component in such a manner that it can be separated from (1)almost quantitatively. Therefore, it is advantageous to useaminocarboxylic acids or aminosulphonic acids as diazo components, suchas, for example

2-aminobenzoic acid

4-aminobenzoic acid

2-aminobenzenesulphonic acid

3-aminobenzenesulphonic acid

4-aminobenzenesulphonic acid

2-amino-4-methylbenzenesulphonic acid

6-amino-2-naphthalenesulphonic acid

7-amino-1,3-naphthalenedisulphonic acid

2-amino-1,5-naphthalenedisulphonic acid

4-amino-1-naphthalenesulphonic acid

5-amino-1-naphthalenesulphonic acid etc.

If the reductions are carried out in a purely aqueous medium, the resultin these cases is mostly solutions from which the benzoic acids oraminosulphonic acids can be precipitated as betaines and separated offby acidification and, if necessary, salting out. (1) remains in theacidic aqueous solution and can be isolated or further reacted, asalready described.

If aniline or α-naphthylamine is selected as possible diazo component,after the reduction it must be separated off from (1) by means of steamdistillation. Other aniline derivatives which are volatile in steam arealso suitable as diazo components.

Compound (1) is used, for example, for the preparation of interestingazo dyestuffs, such as Example 17 from DOS (German PublishedSpecification) 3,512,340 ##STR14## or Example 5 from EP 279,351##STR15## and for the preparation of triphendioxazine dyestuffs, such asExample 1 from EP 153,599 ##STR16##

Azo dyestuffs of the formula (5) and (6) are used for the colouring ofpaper and the dyeing of wool, synthetic polyamide fibres or leather.

Furthermore, azo dyestuffs of the formula (5) and (6) having no sulphoand no carboxy groups are suitable for the dyeing of polyesters andpolyurethanes. Clear, brilliant yellow colorations or dyes are obtained

The formula given for sulpho-containing and carboxyl-containing azodyestuffs are those of the free acids. The preparation in general givesthe salts, in particular the alkali metal salts, such as sodium salts,potassium salts or lithium salts.

EXAMPLE 1

An emulsion of 135 g of benzothiazole and 1 g of a conventionalemulsifier in 500 ml of water is heated to 60° C., and nitrogen ispassed through it for 1 hour. A total of about 300 g of ethylene oxideis then metered in over a period of about 12 hours at such a rate that apH between 9.5 and 10.5 is maintained. The reaction is monitored bythin-layer chromatography. As soon as less than 1% of the startingconcentration of the benzothiazole can be detected, the ethylene oxideaddition is stopped, and the reaction solution is heated at 80° C. for afurther 2 hours, while passing a vigorous nitrogen stream through it.After the remaining ethylene oxide has been removed in this manner, thereaction solution of about 800 ml is cooled to room temperature. Inaddition to glycol and small amounts of polyglycols, the reactionsolution contains a relatively uniform hydroxyethylaniline derivative ofthe formula ##STR17## and can be directly further reacted.

To characterize the product, an 80 ml sample of the solution is workedup at pH 7 by extraction and distillation. A viscous colourless oil isobtained, to which the above structure can be assigned on the basis ofthe ¹ H-NMR and IR data.

IR (Nujol paste): 1662 cm⁻¹ (CO vibr.)

1H-NMR (d₆ -DMSO): δ=3.05 (2H,m); 3.48 (2H,m); 3.60 (2H,m); 3.65 (2H,m);4.68 (t, OH); 4.94 (t, OH); 7.15-7.50 (m, 4H); 8.00 (s, CHO).

Mass spectrum: m/e=241 (M⁺, 45%), 213 (M⁺ --CO, 45%); 182 (65%); 164(55%); 136 (100%).

EXAMPLE 2

200 ml of a 70% strength sulphuric acid are added to 800 ml of thereaction solution from Example 1, and the mixture is heated at 90°-95°C. for 1 hour. It is then cooled, neutralized with concentrated sodiumhydroxide solution and outside cooling and then brought to a pH of 12.5,as a result of which a colourless oil separates.

(However, it is also possible to hydrolyze the reaction solution fromExample 1 under alkaline conditions by bringing it to a pH of 12.5-13.0with sodium hydroxide solution and heating it at 80°-85° C. for 30minutes).

The oil is separated off and characterized as the hydroxyethylaniline ofthe formula ##STR18##

¹ H-NMR (d₆ -DMSO): δ=2.77 (t, 2H); 3.18 (m, 2H); 3.42 (m, 2H); 3.60 (m,2H); 4.81 (t, OH); 4.83 (t, OH); 5.46 (t, NH); 6.50-6.63 (m, 2H); 7.15(m, 1H); 7.30 (m, 1H).

EXAMPLE 3

An emulsion of 149 g of 2-methylbenzothiazole, 1 g of a conventionalemulsifier and 500 ml of water is heated in a pressurized container to60° C., and nitrogen is passed through it for 1 hour. The autoclave isthen sealed and heated to 80° C. About 250 g of ethylene oxide are theninjected over a period of 3 to 4 hours in such a manner that an internalpressure of 1.5 bar and a pH between 9.5 and 10.5 are maintained. Afterthe total amount of ethylene oxide has been added, heating at 80° C. iscontinued until the pressure has dropped to 0.1/-0.2 bar. The pressureis released, and the remaining ethylene oxide is removed by passing avigorous nitrogen stream through the mixture at 80° C. The reactionsolution of about 750 ml is cooled to 20° C. 50 ml of this colourlesssolution are concentrated on a rotary evaporator, and the remaining oilis purified by column chromatography, i.e. glycol and polyglycols areseparated off. A colourless viscous oil is isolated, which is identifiedby spectroscopy as the compound of the formula ##STR19##

¹ H-NMR (d₆ -DMSO): δ=1.65 (s, COCH₃); 3.04 (dt, 1H); 3.12 (t, 2H); 3.50(dt, 2H); 3.63 (t, 2H); 4.08 (dt, 1H); 4.60 (broad, 2 OH); 7.17-7.50 (m,4H).

IR (Nujol): 1640 cm⁻¹ (CO vibration).

Acid or alkaline hydrolysis of these N-acetylaniline compounds produces,in analogy to Example 2, the free base2-(2-hydroxyethylmercapto)-N-(2-hydroxyethyl)aniline.

EXAMPLE 4

23.6 g of the monosodium salt of 7-amino-1,3-naphthalenedisulphonic acidare stirred in 150 ml of water/50 g of ice and 20 ml of concentratedhydrochloric acid, and 17 ml of a sodium nitrite solution (300 g/l) areadded dropwise at 5° to 10° C. The diazotization is completed after 1.5hours. The small excess of nitrite is destroyed by adding sulphamicacid. The cream-coloured suspension is brought to a pH of 2.5 withsodium carbonate solution. A solution of 15.0 g of the free base fromExample 2 in 100 ml of water adjusted to a pH of 2.0 is added dropwiseat about 10° C. The mixture is stirred at 10° C. (pH 1.5-2.0) for 4 to 5hours. To complete the coupling reaction the pH is increased to 4.5 byadding sodium acetate, and the mixture is stirred again for 2 hours. 40g of common salt are added, the mixture is stirred for 1 hour, and theprecipitate is isolated by filtering it off with suction. It is dried togive 48 g of a salt-containing dyestuff of the formula ##STR20##

λmax=454 nm (H₂ O, pH 7-8)

¹ H-NMR (d₆ -DMSO): δ=2.88 (t, 2H); 3.35 (t, 2H); 3.50 (t, 2H); 3.65 (m,2H); 5.15 (broad s, 2 OH); 6.17 (t, NH); 6.85 (d, 1H); 7.83-8.07 (m,4H); 8.16 (s, 1H); 8.30 (s, 1H); 9.30 (s, 1H).

EXAMPLE 5

47 g of the dyestuff from Example 4 are stirred in 250 ml of water at apH of 8-8.5, 0.2 g of sodium tungstate is added, and the mixture isheated to 70° C. 30 ml of an approximately 35% strength aqueous hydrogenperoxide solution are added dropwise. During this addition, thetemperature should be between 70° and 80° C. After about 2 hours, theoxidation is checked by thin-layer chromatography. The sulphoxidederivative which is an intermediate in the oxidation can also bedetected. If necessary, another 10 to 15 ml of hydrogen peroxidesolution are added to also oxidize the remaining sulphoxide derivativeto the sulphone derivative. The mixture is then stirred at 80° C. for 2hours, cooled to room temperature and acidified with sulphuric acid to apH of 0.5 to 1.0. The dyestuff is salted out with 35 g of common saltand 5 g of potassium chloride and isolated. After drying, 38 g of asalt-containing dyestuff of the formula ##STR21## are obtained. On thebasis of TLC and NMR, the azoxy content seems to be no more than a fewper cent.

λmax--406 nm (H₂ O, pH 7-8)

¹ H-NMR (d₆ -DMSO): δ=3.42 (t, 2H); 3.55 (t, 2H); 3.68 (t, 2H); 3.75 (t,2H); 5.0-5.3 (broad, 2 OH); 6.9 (broad s, NH); 7.13 (d, 1H); 7.98 (dd,1H); 8.05-8.17 (m, 2H); 8.20 (s, 1H); 8.27 (d, 1H); 8.32 (d, 1H); 9.35(d, 1H).

In analogy to the coupling procedure (Example 4) and oxidation procedure(Example 5), if the diazo component in Example 4 is varied, it ispossible to prepare further interesting dyestuffs having azosulphide andazo/azoxysulphone structure:

    __________________________________________________________________________     ##STR22##                                                                                                  ##STR23##                                                              λ.sub.max (H.sub.2 O,                                                                λ.sub.max (H.sub.2 O,             Ex.                                                                              D                   pH 7-8)                                                                             Ex.     pH 7-8)                                  __________________________________________________________________________        ##STR24##          432 nm                                                                              11      396 nm                                       ##STR25##          406 nm                                                                              12      374 nm                                       ##STR26##          414 nm                                                                              13      397 nm                                   9                                                                                 ##STR27##          448 nm                                                                              14      402, 455 (sh)nm                          10                                                                                ##STR28##          410, 470 (sh)nm                                                                     15      406, 470 (sh)nm                          __________________________________________________________________________

EXAMPLE 16

12.5 g of 4-aminobenzenesulphonic acid are diazotized analogously toExample 4, and the resulting suspension is brought to a pH of 2.5 withsodium carbonate solution. A solution of 15.0 g of the free base fromExample 2 in 100 ml of water adjusted to a pH of 2.0 is added dropwiseto the suspension at 5° to 10° C. This mixture is stirred at a pH of 1.5to 2.5 at 10° C. for 5 hours and then at pH 3.5 to 4.0 at 10° C. for 3hours. During this procedure, the pH is increased with sodium acetatesolution. After the coupling is completed, the pH is adjusted to 8.0with sodium carbonate solution. A clear solution of the azo dyestuff ofthe formula ##STR29## is obtained. 0.2 g of sodium tungstate is added tothe solution, and the mixture is heated to 60° C. 35 ml of a 35%strength aqueous hydrogen peroxide solution are metered in over a periodof 15 minutes, and the reaction is kept at 70° to 80° C. The oxidationto the sulphone is completed after about 3 to 4 hours. The mixture iscooled to 20° C., brought to a pH of 6.0, and the product is salted outwith 45 g of common salt. After stirring for another 2 hours, it isfiltered off with suction and dried to give 32 g of a golden-yellowdyestuff powder of the structure ##STR30##

λmax=396 nm (H₂ O, pH 7-8)

¹ H-NMR (d₆ -DMSO): δ=3.38 (t, 2H); 3.50 (t, 2H); 3.60-3.75 (m, 4H); 5.0(broad s, 2 OH); 6.94 (t, NH); 7.08 (d, 1H); 7.78 (m, 4H); 8.05 (dd,1H); 8.17 (d, 1H).

EXAMPLE 17

A) 35 g of the dyestuff from Example 5 are dissolved in 150 ml of waterat a pH of 7, 0.2 g of Raney-Nickel catalyst is added, and the dyestuffis reduced in an autoclave with the 2.5-fold equimolar amount ofhydrogen. During this reaction, the batch is allowed to warm to 40° to50° C. After the catalyst has been separated off, a clear, pale brownishsolution is obtained, from which the 7-amino-1,3-napthalenedisulphonicacid can be precipitated in the form of the monosodium salt afteracidification to a pH of 1.0, salting out with 10 g of common salt andcooling to 15° C. The desired [5-amino-2-(2-hydroxyethylamino)phenyl](2-hydroxyethyl) sulphone of the formula ##STR31## remains in solution.The solution can now been directly further reacted, for example afterneutralization, for example with chloranil, such as described in EP153,599. However, it can also be concentrated to dryness on a rotaryevaporator after neutralization. A salt-containing product is thenobtained, which can be purified by recrystallization from water oralcohol and then melts at 130° C.

B) The same product or the same solution is also obtained by reacting 20g of the dyestuff from Example 16 in 100 ml of water at pH 7-8 and 50°C. with 15.5 g of sodium dithionite over a period of 10 minutes. Theinitially golden-yellow solution is decolorized. It is cooled to 20° C.and brought to a pH of 1.5 with hydrochloric acid. After addition of 20g of common salt, it is stirred for 4 to 5 hours until the4-aminobenzenesulphonic acid has completely precipitated. Filtrationgives a solution of relatively uniform[5-amino-2-(2-hydroxyethylamino)phenyl] (2-hydroxyethyl) sulphone.

This important intermediate is also obtained by catalytic hydrogenationanalogously to Example 17 A of the azo/azoxy dyestuffs of Examples 11 to16 and separation of the diazo component D--NH₂ likewise formed, asdescribed.

EXAMPLE 18

18.8 g of [5-amino-2-(2-hydroxyethylamino)phenyl] (2-hydroxyethyl)sulphone are dissolved in 150 ml of water, 50 g of ice and 25 ml ofhydrochloric acid are diazotized at 0° to 3° C. with 17 ml of a sodiumnitrite solution (300 g/l). The diazotization is completed after 30minutes; it results in a solution.

15.2 g of the free base from Example 2 are suspended in 50 ml of waterand dissolved by the addition of 25 ml of acetic acid. This solution isadded to the completely diazotized solution, and the pH is increased to3.5 to 4.0 by adding sodium acetate solution. The reaction temperatureis maintained at 0°-5° C. with ice, and the mixture is stirred at a pHof 3.5 to 4.0 for 8 hours. A crystalline yellow precipitate is formed,which is filtered off with suction, washed with 50 ml of water anddried. 31.5 g of the azo dyestuff of the formula R1 ? ##STR32## areobtained, which can be recrystallized from water or alcohol and melts at177°-178° C.

λmax--458 nm (H₂ O, pH 7-8)

¹ H-NMR (d₆ -DMSO): δ=2.87 (t, 2H); 3.35 (m, 4H); 3.50 (m, 4H);3.60-3.75 (m, 6H); 4.95 (broad s, 4 OH); 6.13 (t, NH); 6.77 (t, NH);6.80 (d, 1H); 7.05 (d, 1H); 7.75 (dd, 1H); 7.90 (d, 1H); 7.95 (dd, 1H);8.07 (d, 1H).

EXAMPLE 19

30 g of the azo dyestuff from Example 18 are suspended in 150 ml ofwater, the mixture is brought to a pH of 8 and, after the addition of0.2 g of sodium tungstate, heated to 60° C. (however, it is alsopossible to use the coupling mixture from Example 18 directly instead ofthe isolated dyestuff). 30 ml of a 35% strength hydrogen peroxidesolution are slowly added dropwise. The reaction is weakly exothermic. Aclear orange-red solution is obtained at 75° C. It is stirred at 75° to80° C. for another hour and then cooled to room temperature. Thisresults in the crystallization of the azo dyestuff in golden-yellowcrystals. To complete the precipitation, 10 g of potassium chloride areadded, and the mixture is cooled to 0° C. The product is filtered offwith suction, washed with a small amount of water and dried at 60° C. invacuo to give 28.2 g of the azo dyestuff of the formula ##STR33## whichcan be recrystallized from water or alcohol and has a melting point of200° C.

λmax--442 nm (H₂ O, pH 7-8)

¹ H-NMR (d₆ -DMSO) 3.38 (t, 4H); 3.50 (t, 4H); 3.62-3.75 (m, 8H); 4.93(t, 2 OH); 4.97 (t, 2 OH); 6.95 (t, 2 NH); 7.06 (d, 2H); 8.01 (dd, 2H);8.12 (d, 2H).

EXAMPLE 20

25.8 g of the azo dyestuff from Example 19 are suspended in 200 ml ofwater, 0.2 g of Raney-Nickel catalyst is added, and the dyestuff ishydrogenated in an autoclave with a 2-fold equimolar amount of hydrogen.The reaction is weakly exothermic; a temperature of 35° to 40° C. isreached. A colourless reaction solution is obtained, if the catalyst isseparated off at 40° C. by filtration. Concentration of the solution ona rotary evaporator gives 26 g of uniform crystalline[5-amino-2-(2-hydroxyethylamino)phenyl] (2-hydroxyethyl) sulphone of theformula ##STR34##

EXAMPLE 21

If diazotized aniline is coupled analogously to Example 16 in aqueousmedium onto the free base2-(2-hydroxyethylmercapto)-N-(2-hydroxyethyl)aniline, and the azocompound obtained is oxidized at 60°-80° C. with hydrogen peroxidesolution, a crystalline azosulphone of the formula ##STR35## isobtained. The golden-yellow compound (λmax=392 nm (H₂ O, pH 7-8) meltsat 126° C.

¹ H-NMR (d₆ DMSO): δ=3.38 (m, 2H); 3.50 (m, 2H); 3.68 (m, 2H); 3.73 (m,2H); 4.90 (t, OH), 4.95 (t, OH); 6.92 (t, NH); 7.08 (d, 1H); 7.45-7.58(m, 3H); 7.80 (d, 1H); 7.86 (d, 1H); 8.04 (dd, 1H); 8.18 (d, 1H).

EXAMPLE 22

20 g of the azo dyestuff from Example 21 are suspended in 200 ml ofwater, 0.2 g of Raney nickel catalyst is added, and the dyestuff ishydrogenated in an autoclave with a 2-fold equimolar amount of hydrogen.A temperature of 40° C. is reached during this process. After thereaction is finished, the catalyst is separated off, and the anilineformed is removed completely from the solution by steam distillation.The remaining solution which contains[5-amino-2-(2-hydroxyethylamino)phenyl] (2-hydroxyethyl) sulphone can beused directly for further reactions, such as, for example, thecondensation with chloranil (cf. Example 17). The above reduction canalso be carried out, for example, in methanol or in a methanol-watermixture.

I claim:
 1. Azo dyestuff of the formula ##STR36## in which D is theradical of a benzene or naphthalene diazo component that isunsubstituted or substituted by Cl, C₁ -C₄ -alkyl, carboxyl,alkylsulphonyl, or sulpho.
 2. Azo/azoxy dyestuff of the formula##STR37## in which D is the radical of a benzene, or naphthalene diazocomponent that is unsubstituted or substituted by Cl, C₁ -C₄ -alkyl,carboxyl, alkylsulphonyl, or sulpho.
 3. Azo dyestuff of the formula##STR38##
 4. Azo/azoxy dyestuff of the formula ##STR39##
 5. Azo dyestuffaccording to claim 1 wherein D is ##STR40## wherein the benzene andnaphthalene rings are unsubstituted or substituted by Cl or C₁ -C₄-alkyl.
 6. Azo/azoxy dyestuff according to claim 2 wherein D is##STR41## wherein the benzene and naphthalene rings are unsubstituted orsubstituted by Cl or C₁ -C₄ -alkyl.